For three dimensional gesture recognition, e.g. the recognition of wipe and approximation gestures, sensors are required that are capable to detect the position, the movement and the orientation of hands.
As an alternative to or in conjunction with camera based systems, the usage of simple LED and photodiode based concepts is of special interest due to the corresponding cost point.
A significant problem known from state of the art is the available assembly space. Different methods have been developed to improve the robustness against external light and other disturbances.
There exist state of the art systems having a generator (G) producing a transmission signal (S5). This transmission signal (S5) drives a transmitter (H). The transmitter (H) transmits into a receiver (D) having passed the transmission path to be measured. The transmission path to be measured consists out of a first partial transmission path (I1) and a second partial transmission path (I2). A controller (CT converts the receiver output signal (S0) of the receiver (D) to a compensation signal (S3). The compensation signal (S3) drives the compensation transmitter (K). The compensation transmitter (K) transmits into the third transmission path (I3). Via the third transmission path (I3) the compensation transmitter (K) transmits typically in a linear superimposing manner into the receiver (D). The controller (CT) generates the compensation signal (S3) out of the receiver output signal (S0) and the transmitter signal (S5) such that the receiver output signal (S0) contains no remaining components of the transmitter signal (S5) with the exception of system noise and a control error. Such systems are called HALIOS systems in the following sections. These systems possess a special robustness against sources of interference, e.g., sun light. Further, HALIOS systems are robust against dirt and receiver (D) drift.
Such a HALIOS system is known from DE102010014462A1 or EP2418512A1 for example.
In general there are two basic HALIOS system versions known from the state of the art. It is possible to mix these two basic HALIOS versions by switching between them or by smooth transitions between the different controller properties. Because the first claim refers to HALIOS systems in general we subsequently give a definition for such state of the art HALIOS systems to be able to keep the claims short and compact.
A HALIOS system as used within this text is characterized                i. that in a first version                    a. It possesses at least one signal generator (G) able to produce at least one transmitter signal (S5), driving at least one transmitter (H) that irradiates into at least one receiver (D) and            b. that it possess at least one controller (CT) producing at least one compensation signal (S3) that drives at least one compensation transmitter (K) which transmits in a superimposing manner into the at least one receiver (D) and            c. that the controller (CT) generates the at least one compensation signal (S3) out of at least one of a receiver output signal (S0) of said receiver (D) and the at least one transmitter signal (S5) and            d. that the controller (CT) drives the at least one compensation transmitter (K) so that the receiver output signal (S0) of the receiver (D) contains no remaining components of the transmitter signal (S5) except for a control error and system noiseor that in a second version            e. that it possesses at least one signal generator (G) able to produce at least one compensation signal (S3), driving at least one compensation transmitter (K), that transmits into at least one receiver (D) and            f. that it possesses at least one controller (CT) producing at least one transmitter signal (S5) that drives at least one transmitter (H) which transmits in a superimposing manner into the at least one receiver (D) and,            g. that said controller (CT) generates the at least one transmitter signal (S5) out of at least one of a receiver output signal (S0) of the receiver (D) and the at least one compensation transmitter signal (S3) and            h. that the controller (CT) drives the at least one transmitter (H) such that the receiver output signal (S0) of the receiver (D) contains no remaining components of the compensation transmitter signal (S3) except for a control error and system noise            or                        ii. that it is a mixture of the first and second version                    and                        iii. that the at least one optical transmitter (H) is able to transmit into a first transmission path (I1) that is only partially part of the apparatus, and        iv. at least one object (O), that is not part of the apparatus and located at the end of the first transmission path (I1), is able to transmit light into at least a second transmission path (I2), that is only partially part of the apparatus and that terminates, at the at least one receiver (D), that is part of the apparatus, and        v. that the at least one receiver (D) is able to receive the transmission signal (S5) modified by the transmission through the first transmission path (I1) and/or the second transmission path (I2) and/or the reflection by the object (O) and to transform the transmission signal (S5) into a receiver output signal (S0) and        vi. that the at least one controller (CT), being part of the apparatus, outputs at least one signal (S4), that may be used outside the apparatus and        vii. that the at least one signal (S4) is a representative measure for at least one property of the at least one first transmission path (I1) or of the at least one second transmission path or at least a representative measure for at least one property of the at least one object (O) at the end of the first transmission path (I1) or at the opening of said second transmission path (I2) and that this measure is output via the output signal (S4) at least on request and        viii. that the compensation transmitter (K) transmits into at least a third transmission path (I3) that is completely part of the apparatus and        ix. that the third transmission path (I3) ends at the at least one receiver (D) and        x. that at least the receiver (D) receives in a superimposing manner at least the signal of the compensation transmitter (K) and the signal of the transmitter (H).        
The assembly of such a HALIOS system into one single SMD package represents several challenges regarding optics and processability.
The DE102010014462A1 does not disclose the required optical system and does not address this problem. One might extract several optical components and special arrangements of optical elements in conjunction with HALIOS systems from DE102010028967A1. In conjunction with the elaboration of this disclosure it was recognized that the backscattering of the light from the compensation transmitter (K) from the receiver (D), typically a photodiode, to the object (O) and then from the object (O) again back to the receiver (D) results in a disturbance signal in the receiver (D). The problem becomes noticeable as an environment dependent basic coupling. This problem is not discussed nor solved in the DE102010028967A1. The semitransparent mirror (e.g. FIG. 9, reference symbol 192 of DE102010028967A1) still results in a continued emission of light from the compensation transmitters (K) that might be scattered towards the object (O).
Patent application DE102012210891A1 discloses an exemplary state of the art package addressing this problem.
There are two potential transmission paths between each transmitter (H) and the object (O) in general: The valuable transmission path (I1 & I2, I3) and a parasitic transmission path. The light of the transmitter (H) may be transmitted from the transmitter (H) to the object (O) first and from there it may be reflected to the photodiode, the receiver (D). The light of the transmitter (H) light should not shine directly onto the photodiode (D). The situation is the opposite for the light of the compensation transmitter (K). It should shine directly on the photodiode (D) and should not be dispersed onto the object (O).
A maximum of transmitted energy should reach the object to be detected and the receiver (D) should detect a maximum of light reflected by the object. In the state of the art DE102012210891A1, for example, proposes a lens that is arranged coaxially to the transmitter or receiver center point. (FIG. 3 of the DE102012210891A1). A problem of the technology disclosed by DE102012210891A1 is that the exterior space illumination is lower in contrast to the illumination within the device embodying the invention. The lenses (reference numbers 218 and 312 of DE102012210891 A1) are lowered relative to the top cover (reference numbers 219 and 319 of DE102012210891A1) by a small rim. This rim further limits the illumination. The DE102012210891A1 achieves the required space illumination by a complex three-dimensional assembly of multiple sensor modules (FIG. 6 of DE102012210891A1). The patent application DE102010027499A1 solves this illumination problem (FIG. 1 of DE102010027499A1) by multiple usage of a module corresponding to DE102010027499A1.
The described illumination problem is similarly solved in the European patent application EP2549652A2. However the three-dimensional assembly is carried out not on module level but on component level. This complex three-dimensional assembly of transmitters and receivers causes an already improved spatial illumination in comparison to DE102012210891A1 (FIGS. 5a and 5b of EP2549652A2). Thereby the lenses are always arranged coaxial to the transmitters and receivers (FIGS. 2 and 4 of EP2549652A2) as disclosed in DE102012210891A1. As before a U-shaped package (reference number 130 of EP2549652A2) causes shadowing effects on the receiver (reference number 200 of EP2549652A2). The trough walls limit its receiver beams.
The international application WO20131134456A1 discloses an assembly of a HALIOS system taking advantage of a glass fiber in a PCB. The transmission diode (reference number 102 of WO20131134456A1) is drawn in FIG. 1 of said patent application in conjunction with a lens. The lens is arranged centrically. Said shadowing problem is caused by the walls of the mounting hole. (reference number 109 of WO20131134456A1). Therefore the illumination is not optimal here as well.
The solution to this problem presented in patent application DE102006020570A1 is significantly better. It is not, however, the objective of the system to supervise the entire open space above the system, but only a limited space immediately above the sensor system. As before, the central lens (reference numbers 21 and 53 of DE102006020570A1) is arranged centrically relatively to the receiver (reference number E of DE102006020570A1). A symmetrical illumination is not possible based on this solution. The transmitters possess lenses.
A significant problem of HALIOS system integration in one package is the suppression of parasitic couplings. The miniaturization increases the problem identified as cross-talk in the following paragraphs. Especially the exposure of the object to be measured to scattered light from the compensation transmitter (K) changes the basic coupling dependent on the usage situation. This situation dependent basic coupling was already described in the European patent application EP2418512A1. In the following disclosure we refer to this patent application and further state of the art publications to differentiate the principles of the disclosure from prior art. First of all we state that all already named publications and all publications referenced in the following description do not address the problem of a situation dependent basic coupling of scattered light from the compensation transmitter.